Mars HYDRO 4" 205CFM Inline Fan with Temperature and Humidity Control

Kyler BurtKyler Burt: Shipping was fast, the product came packaged very well and undamaged. Hooked it all up and everything worked as it should.

I have my controller setup on alarm mode so my fan constantly runs on 3 setting and bumps up to 10 setting when the tent gets too hot or humid. Its kind of hard to setup this way but it is possible! I do wish this unit displayed VPD measurements but for the price i cant complain.

Noise is what it is. I wouldnt want to sleep in the same room as it on 10 setting but its a 6 inch duct fan what can you expect. Its good in my books.

All in all this will be my first grow using this unit and im excited. The controller makes it super simple to regulate temperture and humidity inside the tent. The unit was easy to install and has plenty of extra wires and ducting to place wherever you want. I totally recommend this to whoever is in the market for a 6" duct fan.

Canada on Aug 19, 2023

Rodolfo Pagano: Works very good

Germany on Aug 14, 2023

Colton Stiles: I ordered this fan kit and right out of the box the temperature/humidity wouldn’t read correctly. It would consistently stay in alarm and would beep every second. Contacted Mars hydro and told them about it and they shipped me a new interface and sensor. Plugged them both in, same problem. Haven’t bothered trying again. Everything is rugged and made of quality materials however Both kits I tried didn’t work the way they were supposed to.

Canada on Aug 10, 2023

Daniel H.Daniel H.: Order came damaged all over, broken out pieces, scratches, velcro already applied, screen for module scratched, no packaging except wrapped in foam, unoriginal packaging, and missing the plug completely.
Clearly it was used, abused, and successfully returned. I've initiated a return, we'll see how it goes.

Edit: Refund was successful, ordered it again, and it came as described, packaged perfectly. Works as it should, maybe a little loud, but I am satisfied. I am leaving it 3 stars instead of the original 1 star because what was originially shipped to me was worst case scenario, and should have been caught by Q.A.

United States on Jul 20, 2023

Lillian Olsen: Have not unpacked or used the item yet. Hopefully, it will work whenever I get a chance to use it :)

Germany on Jun 02, 2023

Randy H.: I have trouble with the control settings,fans etc.. Still don’t know, maybe that’s on me,but hope to figure out…the instructions could be better.. this is the 6 inch fan obviously, but I had a 4 in and it only lasted just under a year and had to buy another 4” in which i hope that’s not the case in this fan. Seems like it’s operating just great as far as what i did figure out at the present time!

United States on May 11, 2023

Thane: Overall,I am quite impressed with the unit.Build quality seems excellent and sound levels are quite acceptable at lower air volumes.
2 things to keep in mind:
1) There is no hanging hardware with this unit,contrary to one photo showing straps
2) Use of the thermostat(?) meant my unit cycled from low speed to high to low to high....over and over again in a very short time frame.I now run the unit on continuous speed rather than put up with the constant cycling.I have yet to receive a reply from the manufacturer concerning my issue.I don't see an advantage to having the programmable unit rather than just the rotary speed knob.It would be nice to see this unit allow programming so temp drops low enough in a cycle to stay on low speed for a while.

Canada on Mar 28, 2022

Indigo: This unit does exactly what I needed it to do. I have a 3' x 2'.5'', 4' high grow room and it keep the smell away and the temps where I need them to be. I have my unit set to turn on automatically if temp hits 75 or humidity goes above 50%. Noise is Okay, but you can't expect anything quieter when the fan needs to adjust when your grow space adjusts.
I do wish the 'min temps' setting would be programmed to STOP the units if temps or humidity fall below a certain point, but it does not work that way. That is probably the only downside, it is one or the other.

United States on Jan 01, 2022

Amazon Customer: This is an excellent little in-line fan that seems to pack some power and would be ideal for a 3x3 space. It has a great rate of air exchange that can be turned up or down on their digital controller where you can also set alarms for high/low temps and humidity which can be extremely useful for monitoring purposes- it also comes with the appropriate size carbon filter, ducting, and ducting clamps so you can get everything set up right away! Super convenient and easy to use, an excellent option for your space!

United States on Dec 18, 2021

KellyKelly: I've only been testing this fan/filter for a few weeks, but so far I'm very happy. It moves a ton of air in my 4x4 and the fan (which I installed inside the tent) is decently quiet when cranked up to max settings.

It was very easy to assemble and install, and I have no experience with these kinds of things. I did opt to seal the ducting with aluminum foil tape in addition to the hose clamps -- the tape needs to be bought separately. That said, I don't know if that's even necessary.

The smart monitor is REALLY nifty. Tons of settings to automatically adjust for different scenarios when certain conditions are met. When I thought I had a problem with the monitor (it was actually just me being dumb though) customer support responded to my question in a few hours. Really can't complain!

I'll try to update a year or so down the road and let you know how well it ages. In the meantime though, I'm a happy camper..

United States on Apr 30, 2021